Method of obtaining the radio-active matter in thorium-containing solutions.



UNITED STATES PATENT OFFICE.

FRITZ GLASER, 0F WIESBADEN, GERMANY, ASSIGNOR TO CHARLES GLASER, OF BALTIMORE, MARYLAND.

METHOD OF OBTAINING THE RADIO-ACTIVE MATTER IN THORIUM-CONTAINING SOLUTIONS.

No Drawing.

To all whom it may concern:

Be it known that I, FRITZ GLASER, a subject of the Emperor of Germany, residing at Kapellstrasse 29, Wiesbaden, Germany, have invented certain new and useful Improvements in Methods of Obtaining the Radio- Active Matter in Thorium-Containing Solutions, of which the following is a specification.

The method herewith presented is founded upon the observation, that solutions of thorium salts in presence of phosphoric acid, also in presence of much free mineral acids yield upon dilution with water or when heated, a precipitate of strongly radioactive substances together with thorium phosphate. It is known, that from solutions, which contain thorium and phosphoric acid, also from solutions by mineral acids, upon addition of basic substances, thorium is precipitated as a phosphate. But it is a fact that in this way, with the latter, only little radio-active substance is separated, which even after some time loses a part of its radio activity. In the present method, on the other hand, the precipitation is effected by dilution with much water or by dilution with water and by heating, when the thorium and the radio-active substances precipitate and may be separated from the solution. The latter, after a few days, are then considerably more radioactive maintaining their radio activity, than the thorium-precipitate obtained by addition of basic substances. It suflices to dilute strongly the mineral acid solution, containing phosphoric acid, with water or to heat the same after addition of water, to obtain after sometime a separation which in a few days develops a strong radioactivity which remains constant.

When substances containing thorium, but

Specification of Letters Patent.

Application filed November 1, 1912.

Patented Jan. 20, 1914.

Serial No. 729,154. 5

no phosphoric acid are to be treated, it is necessary to add phosphoric acid or phosphates to the acid solution. As substitutes for them arsenic acid or arseniates may be employed, and with the expression phosphoric acid in the'claims I mean to include any of these substitutes.

I claim:

1. A method of separating the radio-active matter from solutions containing thorium and phosphoric acid, consisting in diluting said solutions with water, whereby a precipitation of thoriumcompounds and radio-active matter is efiected, causing a separation of radio-active matter in the precipitate.

2. A method of separating radioactive matter from solutions containing thorium and phosphoric acid, consisting in diluting said solutions with water and then heating them, whereby precipitation of thorium phosphate is effected, said thorium phosphate carrying down with it the radioactive matter; and in separating said precipitate from the solutions.

3. A method of concentrating radioactive matter, contained in solutions containing thorium phosphoric acid and radioactive matter, consisting in diluting said solutions with water and then heating them, whereby a precipitation of thorium compounds and radioactive matter is effected, and the radioactive matter collected in a precipitate of relatively small bulk.

The foregoing specification signed at Wiesbaden, Germany, this eighteenth day of October, 1912.

DR. FRITZ GLASER.

In presence of two witnesses:

HERMAN PLISOHAR, MARIA MENKE.

. copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

